1. Technical Field
The present invention relates generally to techniques for content delivery.
2. Description of the Related Art
It is known in the art for a content provider to outsource its content delivery requirements to a content delivery network (a “CDN”). A content delivery network is a collection of content servers and associated control mechanisms that offload work from Web site origin servers by delivering content on their behalf to end users. A well-managed CDN achieves this goal by serving some or all of the contents of a site's Web pages, thereby reducing the customer's infrastructure costs while enhancing an end user's browsing experience from the site. For optimal performance, the CDN service provider may maintain an objective, detailed, real-time view of the Internet's topology, reliability, and latency, and this view may then be used to power a dynamic DNS-based system to direct end users to the best CDN server to handle a particular request.
The CDN service provider (or the CDN customer itself) may desire to have a way to constrain a particular customer's use of the CDN in a given manner, e.g., to a given contractual limit. In particular, some CDN customers contract with the CDN service provider to be charged a certain amount for traffic delivered from the CDN servers up to a given “bursting” level. In such cases the customer may desire to avoid a bursting situation, which is typically associated with a higher CDN charge. Thus, for customers that desire to stay within their planned cost budgets, it would be desirable for the CDN service provider to be able to throttle the outbound traffic from a given server or server cluster “on-demand” or under certain circumstances.
The present invention addresses this problem.